Incidence and risk factors of glaucoma after surgery for congenital cataract diagnosed under one year of age: Protocol for Korean Nationwide Epidemiological Study for Childhood Glaucoma (KoNEC)

INTRODUCTION: Congenital cataract (CC) can cause childhood visual impairment, even after CC surgery, due to subsequent occurrence of glaucoma. The post-CC-surgery glaucoma study results vary, due largely to the lack of a sufficient number of population-based cohort studies. This study herein proposed aims to assess the incidence and risk factors of post-CC-surgery glaucoma in a nationwide cohort. The clinico-demographic factors associated with outcomes of post-CC-surgery glaucoma will be investigated as well. MATERIALS AND METHODS: This population-based, nested case-control study is planned as part of the Korean Nationwide Epidemiological Study for Childhood Glaucoma (KoNEC). Data for a nationwide retrospective cohort representative of the years 2008 to 2018 will be extracted from the National Institutes of Health database, which includes demographic information, diagnoses and medical visits as well as procedures, records of prescriptions, and comorbidities. Among the patients whose first CC diagnosis was made before age 1, only those who underwent surgery for CC will be included in the study. The rate of occurrence of post-CC-surgery glaucoma will be determined based on a Poisson distribution. Also, for cumulative incidence plotting, the Kaplan-Meier method will be used. To identify risk factors for occurrence and poor outcomes of post-CC-surgery glaucoma, we will perform a multivariable regression analysis of matched samples. The detailed patterns of post-CC-surgery glaucoma management will be studied as well. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/AWTEC.